Conventional fire protection sprinklers operate primarily due to convective flow of hot gasses past the sprinkler's fusible element. This can render conventional sprinklers ineffective in situations where hot gasses do not reach the fusible element. For example, conventional sprinklers may be ineffective in areas where hot ceiling layers are absent, such as, in installations under grated mezzanines. Similarly, conventional sprinklers may also be ineffective for protecting external, covered storage, and specific hazards such as lubrication oil systems and combustible walls.